During the use of machines powered by internal combustion engines, fuel is consumed and pollution may be generated roughly in proportion to the amount of fuel consumed. Moreover, depending upon whether the internal combustion engine is operated at its peak efficiency configuration, the use of internal combustion engines entails varying degrees of inefficiency in the conversion of fuel to power.
One way to reduce the fuel usage and increase the efficiency of machines that utilize internal combustion engine power is to provide, for example, a hybrid drive system wherein the internal combustion engine provides power that is converted to electric power and used to electrically drive the machine. In a typical hybrid drive system, an electric motor may be coupled to an electrical generator. The generator may receive power from the motor for storage or may provide power to the motor for traction. However, such hybrid drive systems may still involve a certain amount of inefficiency in power transfer and conversion between the motor and generator entities, as well as material used in its construction.